The present invention relates generally to patient ventilation systems and, more particularly, to a uniquely-configured portable continuous positive airway pressure (CPAP) device that may be worn by a patient and which is specifically adapted to provide enhanced patient mobility and comfort as a means to improve patient compliance with prescribed CPAP therapy.
Obstructive sleep apnea (OSA) is a serious breathing disorder affecting as many as one in five adults and is a characterized by a temporary collapse of the throat resulting in a pause in breathing during sleep. Each OSA episode can occur hundreds of times in a single night with each occurrence disrupting the patient's sleep or awakening the patient. Left untreated, OSA can lead to severe and even life-threatening consequences.
The link between OSA and hypertension, stroke and heart failure is well-documented. Serious cases of OSA can result in sleep deprivation or insomnia which, over time, can result in moodiness, irritability, memory loss, poor judgment and an overall poor quality of life. Even further, patients suffering from OSA have a dramatically increased risk of traffic accidents and an increased mortality rate due to medical complications stemming from this disorder.
In severe cases of OSA, doctors prescribe CPAP therapy wherein a constant flow of positively pressurized gas is supplied to the patient during sleep. The gas is typically pressurized to between 5 and 20 cm H2O and is delivered to the patient's airway in order to hold the throat open and allow for uninterrupted breathing during sleep. Conventional CPAP devices typically include a blower unit connected by a patient hose to a mask. The mask acts as a nasal or oral interface and introduces pressurized gas into the patient's throat. The blower unit of conventional CPAP devices is typically powered by an electric motor which, due to noise, vibration and heat produced during its operation, must be mounted on a table or a stand located adjacent the patient's bed to avoid disrupting the patient's sleep.
Conventional CPAP patient hoses are flexible tubes typically provided in a standard six-foot length. The patient hose extends between the bedside blower unit and the mask which is mounted on the patient's head. Because of its long length and because the patient hose extends laterally or sideways from the patient to the blower unit, a sideways “torqueing” or pulling force is imposed by the patient hose on the mask. The torqueing or pulling by the patient hose results in poor sealing of the mask against the patient's face. In addition, the sideways pulling on the mask may also create pressure points against the patient's face and results in general patient discomfort.
For patients who use nasal prongs, the sideways tugging can cause irritation of the patient's nose due to the close-fitting engagement of the prongs with tender mucous tissue lining the patient's nostrils. For patients who use a nasal mask which seals around an exterior of the patient's nose, the tugging of the patient hose can prevent proper sealing of the mask and can also cause eye irritation as a result of pressurized gas leaking around the nose bridge of the mask and flowing into the patient eyes.
Another problem associated with the lengthy patient hose of conventional CPAP devices is the occurrence of condensation in the patient hose. Some conventional motor blower units operate at a relatively high temperature such that the pressurized gas produced thereby is typically heated. As the heated gas travels along the lengthy hose from the blower unit to the patient, the gas cools because the temperature of ambient air in the room is typically lower than the temperature of the pressurized gas. Moisture in the pressurized gas therefore condenses within the hose interior. During a period of use, this condensation can result in water buildup and the patient hose then becomes a breeding ground for bacteria resulting in colds and other health complications for the patient.
Closely related to the problem of tugging by the patient hose is a general lack of mobility associated with conventional CPAP devices. For patients who get up many times during the night, the patient hose acts as a restraint on movement as the patient is effectively tethered to the bedside blower unit. For those with active sleep patterns, the lengthy patient hose inhibits normal body shifting movements and turning from side-to-side to which the patient is accustomed such that the hose makes falling asleep difficult or prevents sleep altogether.
The above-mentioned problems associated with the patient hose are responsible in large measure for the generally low rate of compliance by patients who have started CPAP therapy. Other factors responsible for the low compliance rate include a general dislike of the medical-equipment appearance of a bedside CPAP device in a bedroom environment. Many patients simply have a general aversion to conventional CPAP devices.
As can be seen, there exists a need in the art for a portable CPAP device that provides greater freedom of movement than conventional bedside CPAP devices. More particularly, there exists a need in the art for a wearable CPAP device that provides increased patient mobility but without the problem of the patient hose tugging on the mask as is commonly associated with conventional bedside CPAP devices. In addition, there exists a need in the art for a portable CPAP device that may be constructed in a wide range of configurations that may be conveniently operated in close proximity to the patient without disturbing the patient's sleep.